ZeroEm said:
Toecutter has the KMX frame like the Outrider's are based on.
Outrider made a lot of improvements versus an unmodified KMX frame. To start with, it has indirect steering, to go with its full air shock suspension. It also optimized the frame design to accommodate all of the additional features you won't find on a stock KMX, and is in general, a much stouter platform than a stock KMX.
An Outrider is not perfectly suited to my purposes though, especially given the seat height, but in most respects it's more suited than a stock KMX. Going to an Outrider, I'd be giving up the sort of center of gravity possible with my KMX, in exchange for increased mechanical robustness, a stiffer chassis, more complexity, more weight, probably more comfortable ride(and I find my KMX satisfactory in this regard), bump steer elimination, better battery protection/insulation, and lots of other pros and cons. But you could build quite a bike off of one for sure, especially a velo. I'd try one before buying if possible given the cost involved, but an Outrider is definitely worth investigating if the OP is looking to do the "best" possible trike build.
Are they worth the price? I don't know. Never rode one. I can say my KMX was completely worth the time and money invested in building it up from a framekit and adding all sorts of non-stock components. I'll get the chassis stiffness I'm after with the addition of a custom made roll cage, which will allow for more crash safety than a motorcycle to go with that, and I have the seat so far forward and reclined that on any suitable tire it will be extremely resistant to flipping over, a feature I don't think I'd get with an Outrider unless I put an extremely heavy battery in it when my current design criterion requires a light battery pack.